Manifold for a pile configured battery

Abstract

An improved method of fabricating and discharging a pile configured battery which utilizes an electrically conductive flowing aqueous electrolyte. This is accomplished by use of a single piece hydraulic manifold plate which decouples the hydraulic performance parameters of the manifold from the electrical performance parameters. The manifold plate includes a configuration of hydraulic feed channels and distribution headers which separately account for electrical resistive effects and fluid viscous and dynamic pressure effects. Implementation of such manifold plates allow for improved energy conversion efficiency as well as utilization of multiple dissimilar fluids in a single battery cartridge cell discharge at greatly reduced complexity and cost.

Description

STATEMENT OF GOVERNMENT INTEREST[0001]The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]This invention relates in general to batteries, more particularly to batteries that employ an electrically conductive flowing aqueous electrolyte, and most particularly to batteries that employ an electrically conductive flowing aqueous electrolyte in a stackable cell configuration.[0004]2. Description of the Related Art[0005]A pile configured battery cartridge consists of a group of electrochemical cells, two or more, comprised of flat plate electrodes mechanically stacked one on top of the other. The cell consists of a positive electrode, a negative electrode, and a cell gap separating the two into which a conductive electrolyte flows as required to allow conductive ionic species to trans...

AI Technical Summary

Benefits of technology

[0016]The invention proposed herein comprises a manifold plate for use in pile configured batteries that produces a uniform flow of electrolyte through the cells of the batteries as well as provides a method of sealing the cells without application of unnecessary compressive force. The manifold plate of the present invention also provides for the use of independent fluid pathways for the electrolyte, allowing a user to use two independent electrolyte fluids if desired.

[0018]It is a further object of this invention to provide a manifold for a pile configured batter that reduces the horizontal compressive force on the manifold, so the compressive force focuses on the electrodes within the cells of the battery.

Problems solved by technology

A non, uniform flow distribution through an individual cell results in non uniform heat transfer resulting in a temperature gradient across the cell electrodes.

The impact of the temperature gradient are realized in the form of non uniform electrochemical and corrosion reactions described in Eqs. 1 and 2 resulting in non uniform electrode consumption and reduced cell operating efficiency.

This has the same effect as described for the individual cell, non uniform electrode consumption among cells, non uniform electrochemical conversion efficiency and non uniform generation of reaction products from cell to cell, all of these result in reduced overall cartridge operating efficiency.

This is a major problem which resulted in a hydraulic distribution problem closely coupled. to an electrical circuit problem, each with diametrically opposed approaches to optimization.

The hydraulic problem could not be addressed without having to address the electrical circuit problem and visa versa.

This would not be an issue of concern if it was not for the fact that each of these problems are technically very complicated and, independent of each other, require a great deal of experimental and analytical study.

A related problem with the cast manifold is that a manifold had to be custom fabricated for each specific cartridge containing a different number of cells.

This process could literally take years depending on the magnitude of the variations between cartridge sizes.

The inability to introduce multiple fluids, each one chemically unique, into each cell of the cartridge while maintaining the hydraulic separation of the fluids was not possible with a cast manifold assembly.

In certain pile battery electrochemistry's, it is necessary to operate with separated flows, to do otherwise would render the electrochemistry so inefficient it could not be used.

This allowed for improved performance and cost reduction, but did not allow for separated flow via a single manifold nor did it allow for hydraulic sealing of adjacent manifolds independent of the compressive force applied to the manifold assembly.

While this configuration helped to avoid the problematic results of non-uniform flow of electrolyte through battery cells discussed above, it did not address the compressive force issue discussed above or allowed the introduction of more than one independent fluid pathway into a cell.

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